In this Thursday, May 31, 2018 photo, a temporary worker using a lantern collects white asparagus from a field in Caparroso, around 85 km (52 miles) from Pamplona, northern Spain. Dubbed the “white gold” of these northern Spanish farms because of their color and the high price they fetch in markets and restaurants around the world, the stringy delicacy is planted every fall and picked each year between April and June, at the height of the spring. (Photo by Alvaro Barrientos/AP Photo)

A gallery assistant for Sotheby's auction house admires a melchior of Chateau Cheval Blanc 2006 on February 12, 2010 in London, England. The melchior sized bottle, which is 18 litres in volume, is to be sold in Sotheby's sale of “Finest and Rarest Wines & Vintage Port” on February 17, 2010 in London and is expected to fetch up to 4,800 GBP. (Photo by Oli Scarff/Getty Images)

In this February 22, 2018 photo, a couple looks at a bag made out of Venezuelan Bolivars in La Parada, Colombia, on the border with Venezuela. Each collector item produced by Richard Segovia, sitting at the table, fetches between $10 and $15 – a huge markup from the pennies that bolivars retrieve on Venezuela's black market. (Photo by Fernando Vergara/AP Photo)

“On the Li River near Xingping in China, Cormorant fishermen work the waterways before dawn amidst the spectacular limestone towers of the Karst landscape. The birds are trained to fetch fish from the inky depths but not swallow them. The fisherman accepts the fish from the birds who dive back for more. Here, still before dawn, the fisherman and his birds head for home”. (Photo and caption by Neville Jones/2014 Sony World Photography Awards)

Bonhams expert Michaela Vergottis holds a yellow Jade Chinese Imperial Sceptre on May 9, 2011 in London, England. The piece which is thought to have been taken by British Troups during the Boxer Rebellion is expected to fetch between £800,000 – 1.2 M GBP when it goes on sale at the “Chinese Art” sale at Bonham's auction house on May 12, 2011. (Photo by Dan Kitwood/Getty Images)

A workman jokes besides a work entitled “Monkey Detonator” by Banksy at Bonhams Auction house on September 16, 2011 in London, England. The piece makes up part of the “Urban Art” sale, and is expected to fetch between £70,000 - £90,000 GBP when it goes under the hammer on September 21, 2001 at Bonhams Auction house in London. (Photo by Dan Kitwood/Getty Images)

Tim Klingender, Director of Aboriginal Art at Sotheby's hangs the painting “Emu Corroboree Man” by Clifford Possum Tjapaltjarri before a record auction of Aboriginal Art July 14, 2005 in Sydney, Australia. The painting is expected to fetch AUD 150,000 – 250,000 (USD 120,000 – 200,000). Sotheby's unveiled a selection of Aboriginal art and artifacts after a tour of New York and London, which will go to auction in Melbourne July 25 2005. The total pre-sales estimate of the collection is AUD 6 million – 8.5 million (USD 5 million – 7 million). (Photo by Ian Waldie/Getty Images)

An employee at Christie's auction house examines a complete sub-fossilised elephant bird egg on March 27, 2013 in London, England. The elephant bird egg is expected to fetch 30,000 GBP when it features in Christie's “Travel, Science and Natural History” sale, which is to be held on April 24, 2013 in London. (Photo by Oli Scarff)